Metal detector



FIG. 1 shows a front perspective view of my design for a metal detector;

FIG. 2 shows a right side perspective view thereof;

FIG. 3 shows a rear view thereof;

FIG. 4 shows a left view thereof;

FIG. 5 shows a top view thereof;

FIG. 6 shows a bottom view thereof; and,

FIG. 7 shows a front view thereof. 

The ornamental design for a metal detector, as shown and described. 